How to Read a Tire Sidewall

There is valuable information in that code on the side of your tire. Learn how to read it so you can use it when you need it.

Instructions

Step 1: Consider the first letter Consider the first letter in the code. A designation of P means the tire was designed for passenger cars. LT indicates a light truck.

Step 2: Consider the bracketed numbers Consider the next set of numbers, separated by a slash. The first number is the width of the tire in millimeters from sidewall to sidewall. The second number is the ratio of the sidewall height to the tire's width as a percentage.

Step 3: Consider the construction code Consider the letter that follows the pair of slashed numbers. It indicates how the tire was constructed.

TIP: The letter R stands for radial and B stands for a tire whose layers run diagonally.

Step 4: Consider the maximum load Consider the next numbers in the sequence. This is the maximum load in pounds that the tire can support when properly inflated.

Step 5: Consider the speed rating Consider the final letter in the code. This is the speed rating or maximum service speed for the tire. The letter S indicates a maximum service speed of 112 miles per hour. A rating of A1 corresponds to 3 miles per hour.

Step 6: Drive according to indications Drive according to the specifications indicated on your tires, and you'll be safer and need less maintenance.

FACT: The U.S. Department of Transportation rates tires on the basis of tread wear, traction, and temperature resistance.